1. Field of this Invention
This invention relates to a signal processing apparatus for PAL color video signal, and particularly to such apparatus for processing PAL color video signals when obtained from a video tape recorder or the like in a so-called special reproducing mode.
2. Description of the Prior Art
A video sheet or disk recorder can play back or reproduce recorded video signals not only at normal speed but also in special reproducing modes, such as, still, slow, quick or fast reproducing modes.
Even helical scan video tape recorders have been provided with the ability to perform in such special reproducing modes by using an automatic head tracking system. In such system, a rotary magnetic head of the helical scan VTR is secured on a piezo-ceramic plate which is deflectable in response to a control voltage applied thereto. The piezo-ceramic plate is secured on a rotary disk around which the magnetic tape is wrapped and advanced. The reproducing mode of such VTR is substantially determined by the speed of movement of the tape. Thus, if the tape is stopped, the rotary magnetic head is moved upward or downward by the bi-morph leaf receiving a suitable control voltage in order to trace video tracks recorded on the tape while the latter was advanced at a standard speed. As a result, the same track is repeatedly scanned, and a still-motion picture or image is displayed. If the tape is advanced at twice the normal or standard speed, the magnetic head traces every other track on the tape, and the position of the head is again controlled by the control signal applied to the bi-morph leaf. Thus, still-mode and fast-mode reproductions are achieved.
In the above special reproducing modes, the sequence of the reproduced video signals is different from that of a standard television system. In the case where the VTR handles a NTSC color television signal, signal sequences of the reproduced video signals can be recovered without decoding the chrominance signal component. However, in the case where a
color video signal is handled in the VTR, it is necessary to decode the chrominance signal component and then to encode the chrominance signal in order to restore the correct signal sequence to the reproduced video signals.